In a typical packing operation, articles (i.e., “products”) approach a case packing station or the like via a flowing article stream (e.g., a continuous, semi-continuous, or batch continuous stream having origins in an upstream bulk flow of articles). As such operations/processing lines are more often than not intended to aggregate articles in multiples in furtherance of establishing a multi-pack of articles, e.g., multi-pack cases (e.g., 6, 12, 24 article packs or bundles), stacked trays of arrayed articles, etc., it is necessary to manage, prepare or ready the inflow stream of articles so as to separate the articles into groups or select groups (i.e., for a collated article corresponding to a preselect pack pattern consistent with the case packing objective) as is generally well known. Once grouped or collated, the article group or set may be further processed, such as by being film or corrugated over-wrapped. Notionally, article metering, article separation and collation, and article group loading (e.g., case or carton loading) are requisite steps attendant to a majority of article packaging operations.
Generally, articles are sequentially passed to and through a variety of work stations whereupon the articles are operated upon in furtherance of metering, grouping, spacing apart the groupings, and/or packing/bundling etc. Commonly, a series of conveying mechanisms, e.g., step operated belt conveyors or the like, are provided to transport or selectively transport the articles. For example, and by way of illustration, conveyance mechanisms may be provided in connection to article supply, article infeed, article group sweep/outfeed.
Conveyance and operational or functional transition points generally require attention, care and management. For instance, article conveyance may be specifically arrested via a holding belt or belts as taught by Cruver (U.S. Pat. No. 5,147,027), or via a retaining member or retaining device as taught by Aronsson (U.S. Pat. Nos. 7,726,463 & 8,113,335, respectively), in advance of article grouping via a metering station characterized by track mounted metering pins or bars which engage either or both of a trailing or leading article group “face” during travel about a fixed travel path delimited by the track. Ramifications of such arrest or selective retention are varied, primarily a function of the character of article, e.g., its compressibility or notionally it elasticity, as well as its configuration/center of gravity, etc.). Typically, the “cost” of surge management has been the use of dedicated arresting/retention devices and an attendant methodical, discrete processing step which generally slows article processing.
As to article metering and/or metering and separation operations, approaches disclosed by Peterman et al. (U.S. Pat. Nos. 6,843,360, 7,222,716 & 7,533,768) and Pundsack et al. (WO 2009/124026 A1) generally improve upon, among others, the approaches noted above. The manner of metering and separating product described and shown, namely, one characterized by, among other things, a stationary or fixed transfer plate bridging infeed and sweep conveyors, a product or article transfer device (e.g., a “slip”) and/or a “control device” for at least registering a leading edge or face of the article group on the transfer device or the like, has enjoyed considerable market success, and is generally recognized as a differentiated approach to heretofore known operations.
In addition to being a known, welcome improvement over heretofore incremental advances in or with regard to prior pin metering devices, e.g., see the work of Pazdernik (U.S. Pat. No. 5,201,823) and Anderson et al. (U.S. Pat. No. 4,832,178) which generally and notionally create a select spaced apart condition for and between articles via the imposition of pins between adjacent articles from below, pins which function to restrain an upstream article of adjacent articles while advancing (e.g., pushing) the downstream article of the adjacent articles, the article transfer device is an elegant solution in furtherance of improved processing speed, via among other things, the elimination of article infeed arresting and its inherent stop/start interval. Moreover, further advances embodied in dual slip sheet approaches, such as that disclosed by Pazdernik (U.S. Pub. No. US 2011/0067975), and in an endless loop (i.e., non-retractable) slip sheet, such as that disclosed by Anderson et al. (U.S. Pat. No. 8,011,495), have likewise enjoyed, and continue to enjoy commercial success.
With current metering/metering-separating approaches characterized by track supported metering bars, alignment bars, sweep bars, dual function align-sweep bars, for select engagement of articles part-and-parcel of article grouping operations (e.g., Cruver, Aronsson, Peterman et al. & Pundsack et al.) considered to be welcomed improvements relative to pin metering from below, issues nonetheless remain with regard to operational flexibility, repeatability, changeover, throughput, surge management, and overall process control vis-a-vis improved operative control linkages for, with, between and among the sought after processing operations.
Trackless metering/metering separating has emerged to address a variety of shortcomings of prior track based metering solutions, with advances predicated upon the use of industrial robots. For instance, Applicant's prior work, U.S. Pat. No. 9,315,338 (Peterman et al.), generally and notionally provide a parallel robot, e.g., a delta 2 robot, equipped with an end effector for travel over and into a downstream-most portion of a bulk flow of articles to effectuate sought after article collation and metering. While universally viewed as a welcome cost effective advance over prior approaches in this processing area, Applicant has since directed efforts to improving, among other things, throughput and surge control.
For example, processing versatility remains desirable owing to the disparate character or configuration of or for the articles (e.g., can, bottle, jug, tray, etc.), the size or capacity of the articles (e.g., volume or mass), and/or the character of the article contents, i.e., the nature of the product (e.g., solid, aggregate, liquid (carbonated, non-carbonated)). Moreover, even for a select article processing run, both product and operational conditions may be varied or variable throughout the run owning to, among other things, a lack of homogeneity in the articles of the bulk article flow, or the character of the conveying surfaces of the conveying mechanisms of the line due to spills, periodic wash downs, etc. Further still, with multi-axis robots having enjoyed wide spread use, leveraging multi-axis robot versatility and precision while retaining high speed operation for a robust trackless pin metering approach from above, without breaking the bank, remains a desirable objective and marketplace aim.
In light of the foregoing operational and/or system approaches with regard to article conveying, metering, grouping, and group separation, and presently perceived shortcomings associated with article collation and metering which impact both upstream and downstream operations, it is believed advantageous to provide, among other things, a higher degree of precision, repeatability, product stability, and speed to robotic metering operations. More particularly, it is believed advantageous to eliminate some mechanization from higher degree mechanized multi-axis robots, to provide a system adapted to readily accommodate article surge, and to reliably and repeatedly guide an end effector through a select travel path at select travel rates throughout portions or segments of the travel path, and to have the end effector selectively approach/exit a downstream most end portion of a bulk flow of conveyed articles from above.